Engine light came on....ECU code PO420
Says it is catalyst System Efficiency Below Theshold(bank 1).
Little History: The car has overheated twice in the last month. First time because radiator was cracked. Radiator was replaced. Second time because hose was cracked. Replace hose and radiator cap. I could not replace the thermostat because a nut is striipped but did replace the temp. sensor. I did replace the spark plugs.
Could the thermostat stuck in the open position ( getting cool in October) cause this code?
or do I need a new catalytic converter?
or what else could it be?
What should I check it first?
Says it is catalyst System Efficiency Below Theshold(bank 1).
Little History: The car has overheated twice in the last month. First time because radiator was cracked. Radiator was replaced. Second time because hose was cracked. Replace hose and radiator cap. I could not replace the thermostat because a nut is striipped but did replace the temp. sensor. I did replace the spark plugs.
Could the thermostat stuck in the open position ( getting cool in October) cause this code?
or do I need a new catalytic converter?
or what else could it be?
What should I check it first?
Oct 11, 2008 at 1:27 PM